Weld joint tracking laser cameras are usually designed with a triangulation laser looking ahead at a fixed distance in front of the welding torch. These cameras are sometimes equipped with an additional 2D video color camera located in the same frontal face of the camera viewing the same area as the triangulation laser. These tracking laser cameras cannot monitor the area of the welding torch tip or monitor the position of the welding torch relative to the tracking camera and to the weld joint. Occasional collision of the welding torch with the workpiece or nearby structures may produce permanent deformation and displacement of the welding torch relative to the laser camera, breaking the initial calibration of the robot TCP (Tool Center Point). This relative displacement, if not detected and corrected, may lead to miss-tracking of the weld joint and to weld defects. Such displacement or permanent deformation still occurs even on robots equipped with anti-collision safety tool mount as described in U.S. Pat. No. 6,346,751 (Delfino et al.). U.S. Pat. No. 5,329,092 (Weaver et al.) proposes an alignment gauging block mounted in a fixed location relative to a welding robot. The block has a V-shaped notch into which the welding wire is programmed to pass on a periodic basis. Misalignment of the welding wire is detected if it contacts the sidewalls of the gauging block. The work operation of the robot must be stopped each time an alignment check is desired, and displacement of the torch tip towards the gauging block takes time and space.